Hydrostatic computing-scale.



No. 642,285; Patented 1an. 3o, |900.

s. BENGSTUN.

HYDROSTATIC COMPUTING SCALE.

(Application led Dec. 3, 1898.)

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UNITED STATES PATENT EEICE.

SWAN BENGSTON, OF ST. PAUL, MINNESOTA.

HYDROSTATIC COMPUTING-SCALE.

SPECIFICATION forming part of Letters Patent No. 642,285, dated January 30, 1900- Application filed December 3, 1898. Serial No. 698,168. (No model.)

To all 1072/0771/ t Hetty concern:

Be it known that I, SWAN BENGSTON, a citizen of the United States, residing at St. Paul, in the county of Ramsey and State of Minnesota, have invented certain new and useful Improvements in I-Iydrostatic Computing- Scales; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the gures of reference marked thereon, which form a part of this specification. p

My invention relates to improvements in hydrostatic scales; and the objects of my invention are, tirst,'to provide a hydrostatic computing-scale, second, to provide a hydrostatic scale which may readilybe so adjusted or regulated as to neutralize the effect of atmospheric changes upon the liquid used in the scale, and, third, to provide such scale with effective, but inexpensive, means for guiding and counterbalancing its platform and scoop. These and other objects I attain by the novel construction and arrangement of parts illustrated in the accompanying drawings, in which- Figure 1 is a top View of my scale. Fig. 2 is a side view of Fig. 1 with a scoop added and the lower portion below the platform 30 in section on the line d a in Fig. 1. Fig. 3 is a vertical sectional View on the line b b in Fig. 2. Fig. 4 is a top end View of one ofthe computing plates or strips, showing their position between the glass tubes upon the top 16 of the hollow base 10.

Referring to the various parts in the drawings by reference-numerals, 1 is a round or cylindrical box, the top of which is closed by the round platform 2, secured to the upper edges of the box by the annular rubber flange 3, held by the clamping-ring 4. Close below the rubber ring 3 is formed in the box the annular groove 5, in which is fitted the ring 6. This ring is cut open at one point and has overlapping ends, as shown at 7, and, like the ordinary springs of an engine-piston, is normally disposed to spread and lie in the groove 5; but by means of the thumb-screws 8 it may be closed inward, so as to reduce the surface of the rubber ring 3, which ring, as a part of the platform 2, presses upon the liquid in the box 3 and raises itin the indicatorvtubes 9, which may be of any desired number and height, according to the size of the scale. These glass tubes 9 are fixed in a frame formed by the hollow base 10, extending from the box 1, the two uprights 12 and 13, and the horizontal top piece 1l, which latter is formed with a box or air-chamber 14, (best shown in Fig. 3,) communicating with the upper ends of the tubes, and is hermetically closed by the rubber covering 15 to prevent evaporation of the liquid in the tubes and in the box or vessel 1 communicating with the tubes.

In the cover or top 16 of the base 10 and in the top piece 11 I journal between the glass pipes 9 the upright computing plates or strips 17, 18, 19, and 20, which near their edges have marked upon them the amount in money of the goods placed upon the platform 30 of the scale, according to the price per pound, which is found at the base of each column of amounts, as will presently be more fully described. These computing-plates are provided with the heads 21, by which they maybe easily turned with the opposite side toward the operator, and will then present prices and computing-tables not found on the side normally turned to the operator.

22 are springs secured near below the heads 21 and take hold at 23 in the top of the frame. These springs hold each plate normally with its bottom arm or projection 24 against the stop 25. If the plate be given half a turn to the right, the said arm 24 will touch against the stop 26, which is placed so far back that the plate makes just half a turn when touching it. When the head 21 is released, the spring 22 turns the plate back to its normal position, presenting to view the prices per pound mostly used in the stores which sell goods by weight, while odd prices, seldom used, are on the backs of the plates.

27 is the weight-indicator, and consists of an upright strip with pounds and fractions of pounds marked upon it. In the drawings only five pounds are shown, and those are each divided into eight equal parts; but it is obvious that the indicator may be made of IOO Si claa any desired height and have any denomination of weight and fractions thereof marked upon it.

In a central cavity 28 in the platform or cover 2 rests the supporting-stem 29 of the upper orscale platform 30, on which the goods to be weighed are usually placed,except when of a nature requiring the scoop 3l to hold them. Then the latter is placed upon the platform, as shown in Fig. 2. From the edge of the platform 30 extends upwardly the rod 32, the upper end of which is carried horizontally to and up through the aperture 33 in the arm 34, which extends from the top of the frame. Upon this arm 34 I fulcrum between the lips 35 the beam 36,with the poise 37 screwthreaded upon it, and between the lips 3S I pivot another beam 39, with the poise 40 slidingly fitted upon it. Both of said lbeams or levers are pivoted (at 4l and 42) to the top portion 43 of the rod 32, which, together with the scale-platform 30, is thereby counterbalanced when the poises stand about as shown.

The two beams, standing at right angles to each other, also guide the end portion 43 of the rod 32 about centrally in the large aperture 33 in the arm 34, and thereby prevent sliding Afriction of any of the parts and tilting of the platform 30 and its rod 32, which are thus confined to only a practically vertical movement.

44 is a stationary strip with the price 14 (meaning fourteen cents per pound) marked near its lower end. This strip and the slats 19 and 20 are in the drawings not fully marked with the amounts for the various fractions of pounds, but will be understood from the more fully marked plates 17 and 18', on which the amounts at tive, six, seven, and eight cents per pound are indicated at each one cent of increase, according as the weight increases and drives the liquid upward in all of the tubes.

In operation the cap 45 is removed from the filling-pipe 46 and the liquid, which may be a mixture of alcohol and water or alcohol only, poured in, the scale being tilted to let the air escape from the box l, so that the platform 2 rests directly on the liquid, which should normally stand at zero on the weight-indicator 27 and at the line 47 on the computing scales or plates. The cap 45 is then replaced to prevent escape of the liquid. In weighing, the article to be weighed is placed on the platform 30, which being thereby pressed downward causes the liquid to rise in all the tubes 9. It' the liquid rises, for instance, to 4 on the strip 27, the article is found to weigh four pounds. Now if the price per pound is eight cents the operator places his finger or pencil at 8 under the line 47, and moving it vertically up to the top of the liquid he finds thirty-two cents to be the cost of the weighed goods, and so on, with any number of pounds or fraction thereof at any of the prices marked on the scale.

If the scoop 3l is to be used, it is countervbalanced simply by mov-ing the poise 40 to the stop 43 on its beam 39 and back again to the stop 49, when the scoop is removed.

By turning and thereby moving the poise 37 on its beam the liquid may be very exactly adjusted to the line O or 47 should it expand or contract slightly from changes in the tem perature or other causes; and if such changes should be very great, as in moving the scale from a very cold to a very warm temperature, then the screws `8 may be turned so as to compress or expand the ring 6, and thereby reduce or enlarge the surface of the flexible portion 3 of the platform 2. This is done by throwing on the platform 30 a known weight-say a piece of cast-iron kept for that purpose and weighing five pounds. If the liquid then stands above 5 on the weight-indicatorbecause the heat has made it lighter than usual, then the ring 6 should be allowed to expand until the increase of platform-area within it supports the five-pound weight as much as the dense liquid did in the cold climate, though acting up under a smaller platform, and vice versa. When the scale is thus caused byincrease or decrease of its platform 30 to shw correct weight, the testing-weight is placed one side and the scale is ready for use in any climate or change of temperature.

The rubber covering l5 is very thin and exible, so that the small quantity `of air rising from the tops of the tubes 9 finds no resist-ance. Should, however, the chamber 14 and its covering be exposed to the sun or otherwise get overheated, then the valve 50 will let the expanding air escape, and the valve 51 Vwill let air in again if a vacuum is created when the air-chamber cools off again, Said valves are also accessible for operation by hand for the said purposes and for keeping them in order.

I am aware that it is old to construct scales with liquid confined in a vessel or box, from whence it is driven up into an indicator-tube by a vibrating platform covering the box. I therefore do not claim such scales broadly; but

What I do claim as my invention, and desire to secure by Letters Patent, is-

1. In a hydrostatic scale, suitably' framed, the combination of a vessel or box containing liquid, an up-and-down-vibrating cover o'r platform hermetically closing the top of the box, a series of upright glass tubes communicating at their lower ends with the liquid inl the box; an upright Weight-indicator near one of the tubes, and a series of upright strips or plates arranged with their edges against the sides of the tubes and having near both edges marked upon them numbers indicating various prices per pound and vertically above each of such price-indicating numbers a column of upwardly-increasing numbers, indicating the cost of the goods placed on the scale, substantially as and for the purpose set forth.

2. In a hydrostatic scale, the combination IOO of a liquid-containing vessel or box, having l a hermetioally-closed, up-and-down-vibrating cover, a series of upright glass tubes communicating at their lower ends with the liquid in the box; an upright weight-indicator at the side of one of said tubes, and a series of upright strips, having price and cost indicating gures upon both edges of both sides, and being interposed between the tubes and arranged with their edges adjacent the sides of the tubes, substantially as and for the purpose set forth.

3. In a hydrostatic scale suitably framed, the combination of a liquid-containing box or vessel having a hermetically-closed, up-anddown-vibrating cover or platform, a series of upright glass tubes communicating at their lower ends with the liquid in the box an upright weight-indicator at the side of one of the tubes, and a series of cost-indicators along the sides of the tubes; said cost-indicators being arranged upon or having the form of strips or plates adapted to be turned with either side to the operator, and having price and cost indicating marks upon both sides, and means for limiting the turning of the plate to only half a turn or circle, and means for returning and holding the plate in its normal position, substantially as and for the purpose set forth.

4. In a hydrostatic scale mounted in a suitable frame, the combination with the liquidcontaining vessel or box l, having the hermetically-closed vibrating platform 2, of the scale-platform 30, resting at a single, central point upon the platform 2, the guiding-rod 32, extending from the scale-platform to the upper part of the framework, two beams fulcrumed in the upper part of the frame, at about right angles to each other, and having, each of them, one end pivoted to the upper end of the said guiding-rod, and the other end provided with a poise, substantially as and for the purpose set forth.

5. In a hydrostatic scale, the combination with a liquid-containing box or vessel of an upright weight-indicator and a transparent, upright tube at the side of the indicator and communicating with the liquid in the vessel, said vessel having a hermetically-closed, Vertically-vibrating cover resting upon the liq-l uid and being adapted to support the goods to be weighed on the scale, and means for reducing and increasing the area of said cover which comes in contact with the liquid, substantially as and for the purpose set forth.

In testimony whereof I affix my signature in presence of two witnesses.

SWAN BENGSTON. Witnesses:

A. M. CARLsEN, H. BIELENBERG. 

